As tensions between Nato and Russia have worsened over the Ukraine crisis, Moscow has significantly increased the number of military flights probing Nato airspace. The number of interceptions over the Baltic States trebled last year and Nato members including Britain have stepped up air policing support in the area.

The two RAF Typhoons were operating under a Nato command.

The Russian planes were spotted flying north of Scotland towards the UK. They were in international airspace throughout the incident.

The Bear bombers were not considered a threat at any time, according to sources briefed on the incident.

"The aircraft were identified as Russian Bear aircraft which were escorted by the RAF Typhoon fighters until they were out of the UK area of interest.

"At no time did the Russian military aircraft cross into UK sovereign airspace.”

The Russian press attaché in London could not be reached for comment.

The incident is the latest in a string of probing manoeuvres toward Britain by Russian planes and ships in recent months.

In April, Typhoons out of Lossiemouth again intercepted Bear bombers flying near UK airspace, hours after HMS Argyll was deployed to monitor a destroyer and two other ships from the country as they passed through the English Channel.